One of the tasks on Moodle 2.8 roadmap is making sure that changes and actions that may be important to somebody trigger events.
As you know, in new logging API introduced in 2.7 all triggered events are added to the log and can be viewed in report_log or other custom reports.
Epic issue MDL-45773 was created to gather together all issues that were already reported about missing events/logging and also the results of HQ event coverage testing.
It turned out to be quite a big list and it is possible that some events will be delayed to 2.9. This is the list sorted by user votes
We encourage users to vote and comment about other missing events. TIA